Senate Democratic Leader Chuck Schumer (N.Y.) called on Health and Human Services Secretary Robert F. Kennedy Jr. to immediately declare a public health emergency for measles, blaming the senior Trump administration official for failing to respond to the rapid resurgence of the disease.

Schumer accused Kennedy in a bluntly worded letter Friday of walking “our country into the nation’s largest measles outbreak in 33 years, leading cases to hit a record high a full 25 years after this country eliminated the disease.”

Schumer said what began as a localized outbreak in Texas has now “exploded” into a nationwide health crisis with nearly 1,300 Americans across 38 states reported to have become infected.

“To prevent this historic record high spread from reaching further and to save lives, you should immediately declare a Public Health Emergency for measles,” Schumer wrote.

The Democratic leader expressed his “deep concern” about Kennedy’s “response or lack thereof to the rapid resurgence of measles across the United States.”

“Under your tutelage as secretary, you have undermined vaccines, gutted public health funding, and dismantled core federal protections meant to keep Americans safe,” he wrote.

Schumer cited the mass layoffs of federal health care employees, including infectious disease scientists, the “careless and devastating” freezing of grants and Kennedy’s overhaul of the Advisory Committee on Immunization Practices.

Kennedy last month removed all 17 members from the advisory committee that guides vaccine policy and recommendations for the Centers for Disease Control and Prevention (CDC).

“As a painful but pertinent reminder, you’ve laid off disease experts, canceled National Institutes of Health (NIH) research into vaccine hesitancy, fired scientists from the nation’s top immunization panel, and stripped over $11 billion in federal public health grants including $550 million from Texas during the peak of its outbreak,” he wrote.

He said that resulted in 50 vaccine clinics closing and 21 public health workers losing their jobs in Dallas County alone.

Schumer noted that while measles is a highly contagious virus, it’s also preventable and was declared eliminated in the Untied States in 2000 after years of a nationwide campaign to give children two doses of the measles vaccine.

“This is a catastrophe of your own making. And while families grieved and health departments begged for help, you told the public that ‘it’s not unusual’ to see measles deaths. You pushed vitamin A instead of vaccines,” he said.

And he highlighted that even after Kennedy acknowledged that the MMR vaccine prevents measles, he continued to sow doubts about whether vaccines are linked to autism, something the Democrat called “a dangerous, long-debunked conspiracy theory.”

“Secretary Kennedy, the American people need a public health response. Not political theater. Not conspiracy. Not silence,” Schumer wrote.

Some Republicans on Capitol Hill are coming under more scrutiny for their votes to confirm Kennedy in February.

Sen. Bill Cassidy (R-La.) was pressed Thursday by a reporter for NBC News to “reconcile” his support for Kennedy’s nomination earlier this year with his acknowledgement that vaccine “skepticism” has contributed to the new rise in measles infections.

“First, let’s note that RFK [Jr.] has come out and told people that they should be vaccinated, so that’s easily reconcilable. He is now saying that people should be vaccinated for measles,” Cassidy said.

Sen. Thom Tillis (R-N.C.) was asked about his support for Kennedy during a CNN interview with Jake Tapper.

Tillis told CNN: “The main reason I supported Kennedy was because Bill Cassidy thought that we should see how it plays out.”

Cassidy is up for reelection next year, and Tillis recently announced his retirement.

Schumer in his letter Friday accused Kennedy of continuing to undermine the nation’s vaccine programs.

He called on the secretary to declare a nationwide emergency to expand resources and leverage funding, personnel and other resources toward limiting the outbreak.

Schumer argued that Kennedy’s continued skepticism of vaccine safety, the termination of National Institutes of Health grants for vaccine hesitancy studies and the firing of vaccine experts from the CDC “have undoubtedly exacerbated the severity of the measles outbreak.”